[ipxe-devel] Telling iPXE to only take certain DHCP offers

Greg Jednaszewski jednaszewski at gmail.com
Fri May 6 18:07:53 BST 2011

On May 6, 2011, at 12:53 PM, Michael Brown wrote:
>> Also, while looking at this issue, I came across the use-cached option. 
>> How does that work?  Is it possible to reuse dhcp information from the
>> original PXE rom DHCP query?  e.g.:
>> PXE rom issues DHCP request
>> DHCP server responds with IP address, filename, and next-server
>> iPXE loads and reuses the cached info from the previous step
> Yes, this should be possible.  In most cases it's unlikely to be what you 
> want, since the original DHCPDISCOVER will not have requested options that may 
> be meaningful to iPXE (such as the SAN root-path).

In my particular case, the only options I care about are IP, netmask, next-server, and possibly gateway which should all be present in the initial DHCP response used by the PXE ROM.  I use the next-server field to find the config server to chainload a more detailed config script via HTTP (based on MAC address).

Do I need to do anything special to make this work besides this?  I'm using undionly.kpxe + an embedded script.

set use-cached 1
dhcp net0


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